Carbureter.



J. W. STEVENS.

CARBURETER.

APPLICATION FILED DEC. 19, 1914. v L1 Patented May 30, 1916.

NI'T/YESSEJ JOHN W.\STEVENS,OF ST. PAUL, MINNESOTA;

CARBURE'DER.

Speccationof Letters Patent.

lllatentedllllay 30, 1916;.r

Application filed December 19, 1914. Serial No. 878,164.

To all whom t may concern.'

Be it known that I, JOHN W. STEVENS, a citizen of the United States, resident of St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in Carbureters, of whichthe followingis a specification.

The object of my invention is'to provide a carbureter in which the suction ports through which the mixture passes to the cylinders can be increased in effective area for increased speed of the engine, and the auxiliary lor variable air ports alsoincreased, but in less proportion or ratio to provide for increased suction at the nozzle.

Other objects of the invention will appear from the following detailedI description. y

The invention consists generally in various constructions and y combinations, all as hereinafter described and particularly pointed out in the claims.

In the accompanying drawings forming part of this specification, Figure 1 is a vertical sectional view of a carbureter embodying my invention, Fig. 2 is a detail view of the cylinder throttle valve, Fig. 3 .is a sectional view on the line xof Fig. 1, Fig. l is a sectional view on the line y-g/ of Fig. 1, Fig. 5 is a detail view, partially in section, of a modified construction.

ln the drawing, 2 represents a casing having a fuel chamber or reservoir 3 communiv eating through a passage 4L and a valve V5 with a source of fuel supply, not shown. rlhe movement of thevalve is controlled by the usual float 6, which encircles an: inner casing or shell 7 between which and the walls of the casing 2 the reservoir isformed. The casing 2 has a removable top 8 to allow access to a chamber 9 within the casing 7 through the open top 10 of said chamber. From this chamber a passage 11 leads to the engine cylinder, (not shown). In the base of the casing 7 is ay hydro-carbon fuel duct 12 communicating with the chamber 8, and with a nozzle 13 which projects up into the cha1nber'9 and is provided with a needle valve 14 by means of which the flow of fuel through the nozzle is controlled in the usual way.

Within the casing 7 I provide a ycylindrical member 15 having an annular flange 16 that is seated in the wall ofthe casing 7 near the middle portion thereof and separates the lower portion of this chamber from the upper portion. This member 15 is provided b'elowsaidflange with variable airintakeports-l? extending vertically therein at intervals and spaced apart and communieating` with the' lower portion of the cham-- ber 9 and with thel open air through the passage 18-across which the duct 12 extends. Above the flange 16 suction ports 19 are formed in said cylindrical member. These ports 17` and 19 have preferably parallel vertical edges and converging end edges, so that theY openings gradually increase inv area from one longitudinal edge toward the opposite edge and the ports are oppositely arranged', that is, the ends converge in one direction inthe upper group of ports and in the opposite direction in the lower group of ports, and as the openings in the upper ports increase in effective area through the movement ofthe throttle, tlie ports in the lower groupwill also increase, but in less proportion.

Fitting within the cylinder 15 is a hollow, member 20 substantially in the form of a truncated cone having a flange 21 seated against the lower end ofthe cylinder l5, the fuel supply nozzle 13 projecting upwardly into said member and' terminating beneath and near fixed air intake ports 22 provided in the upper portion of said member. The cylinder 15 and the member 2O are normally stationary, and the ports 22 admit the gas mixture to the space within the cylinder 15.

Within this cylinder l5 l provide a throttlel valve 23, cylindricalin form, seated at its lower end' on the flange 21 and having ports 24C above the flange 16, and similar ports 25 below the flange 16, adapted to register respectively with the ports 1 9 and 17 in the stationary cylinder. The valve 23 has a stem 26 provided with a lever 27 that is actuated by an arm 28 on a rock shaft 29 that is operated through a suitable mechanism extending to the drivers seat. The cylinder 23 constitutes, in eect, the throttle of the engine for by rotating it the driver can increase or decrease the are-a of the air ports in the cylinder 15 according to atmospheric conditions or the load on the engine. A; stop pin 30 maybe provided on the inner cylinder adapted to enter a notchcl in the cylinder 15, and limit the rotating movement of the inner cylinder. `The suction ports 19 will be partially open even when the trottle is rotated to entirely close the air ports 17, and, owing to the difference in shape of these ports, the movement of the throttle in one direction to increase the area of the suction ports will, while increasing the width of the opening in the air ports 17, atV the same time reduce their length and the proportion of increase in area in the ports 17 will therefore beless than in the suction ports and the `vacuum around the nozzle will be increased and the feed of the fuel quickened. I am thus able to enlarge the suction ports at will and increase the vacuum around the nozzle without at the same time introducing a proportionately greater l volume of air through the auxiliary or variable intake ports. Generally in carbureters thev increase in speed to increase the suction will open the auxiliary valveand admit a correspondingly greater volume of air, which has the eHect of reducing the vacuum at the nozzle, but inmy improvement this objection is avoided, as the movement of the throttle to increase the elective area of the suction ports through which'the mixture is delivered to the cylinder, while opening the Y auxiliary ports, will do so in alesser degree ,than fthe suction ports and the vacuum around the nozzle will be increased instead of reduced. v Y

In Fig. 5f I have shown a modified construction inl which an outer cylinder 32 is provided having ports 33 and 34: therein correspondingsubstantially to the ports 17 and 19 except that they are horizontally instead of Vverticallyfarranged in the cylinders. Both are taperedfrom one end toward the other, they tapervof'one group of ports being the reverse of the taper of the other group. W ithin this cylinder is a slidingthrottle35 having rectangular ports 36 io f Y. inthe cylinder instead of in a rotary directherein adapted to register respectively with thefports 33 andl and movable vertically tion. lIhe .function of thisinner lcylinder 'j is substantially the same as `the one. de-

scribed in referenceto Fig. V1. The inner. cylinder will have aysuitable link connection 37 with a suitableoperating means, (not l I claim as my invention.: t

1. A carbureter comprisingra casing, a sleeve arrangeclwithin said casing and havt ing'an annular `flange that is seated against the'vwalls Vof said casing dividing the space vtherein into an upper and a lower chamber, said sleeve having a group of ports in its upper portion above said flange and a similar group in itsV lower portion below said flange, said ports having tapered walls and decreasing in areafrom one side toward the other, the taper of the upper group of ports being oppositely arranged from that of the lowery group of ports, a throttle valve for closing said ports, the movement of said valve in one direction increasing the length oftheupper ports andcorrespondingly decreasing-the length of the lower ports, a cone shaped member projecting into the lower portion of said sleeve and having a series of lixed ports therein, the chamber below said iiange communicating with the,ports of said cone shaped member and with the lower group of ports in said sleeve, and with an air intake, and a fuel supply nozzle projecting into said cone shaped member.

2. A carbureter comprising a casing having an air intake opening and a passage for communication with the engine cylinders, a sleeve mounted in said casing and having ports in its lower portion communicating with said air intake passage and ports in its upper portion communicating with the passage to the engine cylinders, said ports having tapered walls, those of one group being oppositely arranged with respect to those of the other group, a throttle valve mounted for rotation in said sleeve and having groups of ports arranged to register respectively with the groups of ports of said sleeve, the oppositely arran ed taper of said sleeve ports providing or an increase in area of one group of sleeve ports and an increase in area of the other group of ports, but in a different ratio, a cone shaped member having ports therein fitting within said sleeve and communicating with said air intake passage, and a fuel supply nozzle projecting into said cone shapedmember adjacent to the fixed ports therein.

v 3. A carbureter comprising a casing having inlet and outlet openings and a nozzle projecting through said inlet opening, concentric, relatively-movable members mounted within said casing and having upper and lower groups of ports opened and closed by the movement of one of said members, one of said members having an opening therein to receive said nozzle and a member encircling` said nozzle and provided with ports, the movement of one of said concentric members in one direction increasing the area of the upper and lower groups of ports but increasing the area ofthe lower group in less proportion.

- 4. A carbureter comprising a casing having a chamber formed therein provided with inlet and outlet openings and a fuel supply nozzle projecting into said chamber through said inlet opening, cylindrical members concentrically mounted withinV said chamber and relatively movable and one of them forming a throttle, means separating the space in said chamber around the lower portion of said cylinders from the space in said chamber around the upper portion of said cylinders, one of said cylinders having a central opening into which said nozzle projects and a member encircling said nozzle, the upper portion of the walls of said encircling member having a series of ports therein, the ports in the upper portion of said cylindrical members communicating with the upper part of said chamber and the ports in the lower walls of said cylindrical member communicating with the lower part of said chamber, the upper group of ports in one member increasing in elective area with the movement of the throttle in one direction and the other group of ports also increasing in area with the movement of said 1,184,889 Y jz;

throttle but in less proportion, thereby increasing the suction at the nozzle. 1o

In witness whereof l have hereunto set my hand this 14th day of December, 1914:. JOHN W. STEVENS.

Witnesses Q GENEVIEVE E. SORENSEN, EDWARD A. PAUL. 'a

Gomes of this patent may be obtained for ve cents each, by addressing' the Commissioner of Patente, ll

Washington, ZD. U. .sr 

